Monday, March 8, 2010

The Modal Cosmological Argument's Possibility Premise

I have been working on a Modal Cosmological Argument (MCA) for some time now, and I'm convinced that the key premise - the possibility premise - is rationally acceptable. However, given recent attempts at proving that a maximally great being is possible (see my previous post), demonstrating the possibility of a necessary being ought to be even easier, assuming that such a proof is correct. Before I provide the possibility proof, here's another look at the MCA:

1. Contingent beings exist.
2. It is possible that the collection of all contingent beings (CCB) has an external cause.
3. If an external cause exists, that cause is a necessary being.
4. Hence, a necessary being possibly exists.
5. Whatever is possibly necessary is necessary.
6. Therefore, a necessary being exists.

Let's reformulate the three axioms listed earlier:

A1. If a property is a great-making property, its negation is not a great-making property.
A2. If a property A is a great-making property and the property B is a necessary condition for A, then B is a great-making property.
A3. Being a necessary being is a great-making property.

Following these axioms is the proof that a necessary being possibly exists:

P1. If it's not possible that a necessary being exists, then every being has the property of being contingent.
P2. If every being has the property of being contingent, then being contingent is a necessary condition.
P3. If being contingent is a necessary condition, then being contingent is a great-making property. (From A2)
P4. Being contingent is not a great-making property. (From A1 and A3)
P5. Therefore, it is possible that a necessary being exists.


  1. This is clever. You can extend the argument to get the conclusion that God exists. Let God be a being that is maximally great in all possible worlds. Then suppose there is no God. Then not being God will be a necessary condition on every great-making attribute. But clearly not being God is not a great-making attribute.

    Someone might object that "not being God" is not an attribute because of the "not". But then there's the same problem with "contingent", which means "not-necessary and not impossible"...

    However, one can also extend your argument to show that a necessarily existing teapot exists by the same reasoning above--since not being a necessarily existing teapot isn't a great-making property. Thus, it seems the premise that A2 actually implies an absurdity. Thus, A2 is most likely false.

  2. I think not being a teapot (necessary or contingent) is a great-making property. ;)